fly/flightgear
1
0
Fork 0
Code Activity

Further re-factoring of nav-radio code, again no functionality changed should occur. Radio reception / GPS slaving / Glideslope handling and CDI updating are all separate functions now.

Browse source
This commit is contained in:
jmt 2009-09-08 14:23:44 +00:00 committed by Tim Moore
parent e8db3a514a
commit e2f0d1960e
2 changed files with 211 additions and 228 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

423
src/Instrumentation/navradio.cxx
View file

@ -299,16 +299,10 @@ double FGNavRadio::adjustILSRange( double stationElev, double aircraftElev,
void
FGNavRadio::update(double dt)
{
// Do a nav station search only once a second to reduce
// unnecessary work. (Also, make sure to do this before caching
// any values!)
_time_before_search_sec -= dt;
if ( _time_before_search_sec < 0 ) {
search();
if (dt <= 0.0) {
return; // paused
}
bool inrange = false;
// Create "formatted" versions of the nav frequencies for
// instrument displays.
char tmp[16];
@ -317,87 +311,79 @@ FGNavRadio::update(double dt)
sprintf( tmp, "%.2f", alt_freq_node->getDoubleValue() );
fmt_alt_freq_node->setStringValue(tmp);
if (_navaid
&& power_btn_node->getBoolValue()
if (power_btn_node->getBoolValue()
&& (bus_power_node->getDoubleValue() > 1.0)
&& nav_serviceable_node->getBoolValue() )
{
inrange = updateWithPower(dt);
if (nav_slaved_to_gps_node->getBoolValue()) {
updateGPSSlaved();
} else {
updateReceiver(dt);
}
updateCDI(dt);
} else {
inrange_node->setBoolValue( false );
cdi_deflection_node->setDoubleValue( 0.0 );
cdi_xtrack_error_node->setDoubleValue( 0.0 );
cdi_xtrack_hdg_err_node->setDoubleValue( 0.0 );
time_to_intercept->setDoubleValue( 0.0 );
gs_deflection_node->setDoubleValue( 0.0 );
to_flag_node->setBoolValue( false );
from_flag_node->setBoolValue( false );
clearOutputs();
}
updateAudio(inrange);
updateAudio();
}
bool FGNavRadio::updateWithPower(double dt)
void FGNavRadio::clearOutputs()
{
bool nav_serviceable = nav_serviceable_node->getBoolValue();
bool cdi_serviceable = cdi_serviceable_node->getBoolValue();
bool tofrom_serviceable = tofrom_serviceable_node->getBoolValue();
double az1, az2, s;
inrange_node->setBoolValue( false );
cdi_deflection_node->setDoubleValue( 0.0 );
cdi_xtrack_error_node->setDoubleValue( 0.0 );
cdi_xtrack_hdg_err_node->setDoubleValue( 0.0 );
time_to_intercept->setDoubleValue( 0.0 );
gs_deflection_node->setDoubleValue( 0.0 );
to_flag_node->setBoolValue( false );
from_flag_node->setBoolValue( false );
}
void FGNavRadio::updateReceiver(double dt)
{
// Do a nav station search only once a second to reduce
// unnecessary work. (Also, make sure to do this before caching
// any values!)
_time_before_search_sec -= dt;
if ( _time_before_search_sec < 0 ) {
search();
}
if (!_navaid) {
_cdiDeflection = 0.0;
_cdiCrossTrackErrorM = 0.0;
_toFlag = _fromFlag = false;
_gsNeedleDeflection = 0.0;
inrange_node->setBoolValue(false);
return;
}
SGGeod pos = SGGeod::fromDegFt(lon_node->getDoubleValue(),
lat_node->getDoubleValue(),
alt_node->getDoubleValue());
bool inrange = false;
if ( nav_slaved_to_gps_node->getBoolValue() ) {
// FIXME - GPS-slaved GS support in unfinished
has_gs_node->setBoolValue(gps_has_gs_node->getBoolValue());
inrange = gps_to_flag_node->getBoolValue() || gps_from_flag_node->getBoolValue();
} else {
inrange = inrange_node->getBoolValue();
}
double nav_elev = _navaid->get_elev_ft();
SGVec3d aircraft = SGVec3d::fromGeod(pos);
double loc_dist = dist(aircraft, _navaid->cart());
loc_dist_node->setDoubleValue( loc_dist );
bool is_loc = loc_node->getBoolValue();
double signal_quality_norm = signal_quality_norm_node->getDoubleValue();
if (_gs) {
// find closest distance to the gs base line
double dist = sgdClosestPointToLineDistSquared(aircraft.data(), _gs->cart().data(),
gs_base_vec.data());
gs_dist_node->setDoubleValue( sqrt( dist ) );
// cout << "gs_dist = " << gs_dist_node->getDoubleValue()
// << endl;
// wgs84 heading to glide slope (to determine sign of distance)
SGGeodesy::inverse(pos, _gs->geod(), az1, az2, s);
double r = az1 - target_radial;
SG_NORMALIZE_RANGE(r, -180.0, 180.0);
if (fabs(r) <= 90.0) {
gs_dist_signed = gs_dist_node->getDoubleValue();
} else {
gs_dist_signed = -gs_dist_node->getDoubleValue();
}
} else {
gs_dist_node->setDoubleValue( 0.0 );
}
double az2, s;
//////////////////////////////////////////////////////////
// compute forward and reverse wgs84 headings to localizer
//////////////////////////////////////////////////////////
double hdg;
SGGeodesy::inverse(pos, _navaid->geod(), hdg, az2, s);
heading_node->setDoubleValue( hdg );
heading_node->setDoubleValue(hdg);
double radial = az2 - twist;
double recip = radial + 180.0;
SG_NORMALIZE_RANGE(recip, 0.0, 360.0);
radial_node->setDoubleValue( radial );
recip_radial_node->setDoubleValue( recip );
//////////////////////////////////////////////////////////
// compute the target/selected radial in "true" heading
//////////////////////////////////////////////////////////
@ -446,133 +432,66 @@ bool FGNavRadio::updateWithPower(double dt)
signal_quality_norm, dt );
signal_quality_norm_node->setDoubleValue( signal_quality_norm );
if ( ! nav_slaved_to_gps_node->getBoolValue() ) {
/* not slaved to gps */
inrange = signal_quality_norm > 0.2;
}
bool inrange = signal_quality_norm > 0.2;
inrange_node->setBoolValue( inrange );
//////////////////////////////////////////////////////////
// compute to/from flag status
//////////////////////////////////////////////////////////
if (tofrom_serviceable) {
if (nav_slaved_to_gps_node->getBoolValue()) {
to_flag_node->setBoolValue(gps_to_flag_node->getBoolValue());
from_flag_node->setBoolValue(gps_from_flag_node->getBoolValue());
} else if (inrange) {
bool toFlag = false;
if (is_loc) {
toFlag = true;
} else {
double offset = fabs(radial - target_radial);
toFlag = (offset > 90.0 && offset < 270.0);
}
to_flag_node->setBoolValue(toFlag);
from_flag_node->setBoolValue(!toFlag);
} else { // out-of-range
to_flag_node->setBoolValue(false);
from_flag_node->setBoolValue(false);
if (inrange) {
if (is_loc) {
_toFlag = true;
} else {
double offset = fabs(radial - target_radial);
_toFlag = (offset > 90.0 && offset < 270.0);
}
_fromFlag = !_toFlag;
} else {
to_flag_node->setBoolValue(false);
from_flag_node->setBoolValue(false);
_toFlag = _fromFlag = false;
}
//////////////////////////////////////////////////////////
// compute the deflection of the CDI needle, clamped to the range
// of ( -10 , 10 )
//////////////////////////////////////////////////////////
double r = 0.0;
bool loc_backside = false; // an in-code flag indicating that we are
// on a localizer backcourse.
if ( cdi_serviceable ) {
if ( nav_slaved_to_gps_node->getBoolValue() ) {
r = gps_cdi_deflection_node->getDoubleValue();
// We want +- 5 dots deflection for the gps, so clamp
// to -12.5/12.5
SG_CLAMP_RANGE( r, -12.5, 12.5 );
} else if ( inrange ) {
r = radial - target_radial;
// cout << "Target radial = " << target_radial
// << " Actual radial = " << radial << endl;
SG_NORMALIZE_RANGE(r, -180.0, 180.0);
if ( fabs(r) > 90.0 ) {
r = ( r<0.0 ? -r-180.0 : -r+180.0 );
} else {
if (is_loc) {
loc_backside = true;
}
}
r = -r; // reverse, since radial is outbound
if ( is_loc ) {
// According to Robin Peel, the ILS is 4x more
// sensitive than a vor
r *= 4.0;
}
SG_CLAMP_RANGE( r, -10.0, 10.0 );
r *= signal_quality_norm;
}
// CDI deflection
double r = radial - target_radial;
SG_NORMALIZE_RANGE(r, -180.0, 180.0);
if ( fabs(r) > 90.0 ) {
r = ( r<0.0 ? -r-180.0 : -r+180.0 );
}
cdi_deflection_node->setDoubleValue( r );
//////////////////////////////////////////////////////////
// compute the amount of cross track distance error in meters
//////////////////////////////////////////////////////////
double xtrack_error = 0.0;
if ( inrange && nav_serviceable && cdi_serviceable ) {
r = radial - target_radial;
SG_NORMALIZE_RANGE(r, -180.0, 180.0);
if ( fabs(r) > 90.0 ) {
r = ( r<0.0 ? -r-180.0 : -r+180.0 );
}
r = -r; // reverse, since radial is outbound
xtrack_error = loc_dist * sin(r * SGD_DEGREES_TO_RADIANS);
} else {
xtrack_error = 0.0;
r = -r; // reverse, since radial is outbound
_cdiDeflection = r;
if ( is_loc ) {
// According to Robin Peel, the ILS is 4x more
// sensitive than a vor
// http://www.allstar.fiu.edu/aero/ILS.htm confirms both the 4x sensitvity
// increase, and also the 'full-deflection is 10-degrees for a VOR' clamp
_cdiDeflection *= 4.0;
}
cdi_xtrack_error_node->setDoubleValue( xtrack_error );
SG_CLAMP_RANGE(_cdiDeflection, -10.0, 10.0 );
_cdiDeflection *= signal_quality_norm;
// cross-track error (in metres)
_cdiCrossTrackErrorM = loc_dist * sin(r * SGD_DEGREES_TO_RADIANS);
updateGlideSlope(dt, aircraft, signal_quality_norm);
last_loc_dist = loc_dist;
}
//////////////////////////////////////////////////////////
// compute an approximate ground track heading error
//////////////////////////////////////////////////////////
double hdg_error = 0.0;
if ( inrange && cdi_serviceable ) {
double vn = fgGetDouble( "/velocities/speed-north-fps" );
double ve = fgGetDouble( "/velocities/speed-east-fps" );
double gnd_trk_true = atan2( ve, vn ) * SGD_RADIANS_TO_DEGREES;
if ( gnd_trk_true < 0.0 ) { gnd_trk_true += 360.0; }
SGPropertyNode *true_hdg
= fgGetNode("/orientation/heading-deg", true);
hdg_error = gnd_trk_true - true_hdg->getDoubleValue();
// cout << "ground track = " << gnd_trk_true
// << " orientation = " << true_hdg->getDoubleValue() << endl;
void FGNavRadio::updateGlideSlope(double dt, const SGVec3d& aircraft, double signal_quality_norm)
{
if (!_gs || !inrange_node->getBoolValue()) {
gs_dist_node->setDoubleValue( 0.0 );
return;
}
cdi_xtrack_hdg_err_node->setDoubleValue( hdg_error );
//////////////////////////////////////////////////////////
// compute the time to intercept selected radial (based on
// current and last cross track errors and dt
//////////////////////////////////////////////////////////
if (dt > 0) { // Are we paused?
double t = 0.0;
if ( inrange && cdi_serviceable ) {
double xrate_ms = (last_xtrack_error - xtrack_error) / dt;
if ( fabs(xrate_ms) > 0.00001 ) {
t = xtrack_error / xrate_ms;
} else {
t = 9999.9;
}
}
time_to_intercept->setDoubleValue( t );
}
// find closest distance to the gs base line
double dist = sgdClosestPointToLineDistSquared(aircraft.data(), _gs->cart().data(),
gs_base_vec.data());
dist = sqrt(dist);
gs_dist_node->setDoubleValue(dist);
double heightAboveStationM =
(alt_node->getDoubleValue() - _gs->elevation()) * SG_FEET_TO_METER;
//////////////////////////////////////////////////////////
// compute the amount of glide slope needle deflection
// (.i.e. the number of degrees we are off the glide slope * 5.0
@ -584,53 +503,87 @@ bool FGNavRadio::updateWithPower(double dt)
// needle animation. This means that the needle should peg
// when this values is +/-3.5.
//////////////////////////////////////////////////////////
r = 0.0;
if (_gs && gs_serviceable_node->getBoolValue() ) {
if ( nav_slaved_to_gps_node->getBoolValue() ) {
// FIXME what should be set here?
} else if ( inrange ) {
double x = gs_dist_node->getDoubleValue();
double y = (alt_node->getDoubleValue() - nav_elev)
* SG_FEET_TO_METER;
// cout << "dist = " << x << " height = " << y << endl;
double angle = atan2( y, x ) * SGD_RADIANS_TO_DEGREES;
r = (target_gs - angle) * 5.0;
r *= signal_quality_norm;
}
}
gs_deflection_node->setDoubleValue( r );
double angle = atan2(heightAboveStationM, dist) * SGD_RADIANS_TO_DEGREES;
double deflectionAngle = target_gs - angle;
//SG_CLAMP_RANGE(deflectionAngle, -0.7, 0.7);
_gsNeedleDeflection = deflectionAngle * 5.0;
_gsNeedleDeflection *= signal_quality_norm;
//////////////////////////////////////////////////////////
// Calculate desired rate of climb for intercepting the GS
//////////////////////////////////////////////////////////
double x = gs_dist_node->getDoubleValue();
double y = (alt_node->getDoubleValue() - nav_elev)
* SG_FEET_TO_METER;
double current_angle = atan2( y, x ) * SGD_RADIANS_TO_DEGREES;
double target_angle = target_gs;
double gs_diff = target_angle - current_angle;
double gs_diff = target_gs - angle;
// convert desired vertical path angle into a climb rate
double des_angle = current_angle - 10 * gs_diff;
double des_angle = angle - 10 * gs_diff;
// estimate horizontal speed towards ILS in meters per minute
double dist = last_x - x;
last_x = x;
if ( dt > 0.0 ) {
// avoid nan
double new_vel = ( dist / dt );
double elapsedDistance = last_x - dist;
last_x = dist;
double new_vel = ( elapsedDistance / dt );
horiz_vel = 0.75 * horiz_vel + 0.25 * new_vel;
horiz_vel = 0.75 * horiz_vel + 0.25 * new_vel;
// double horiz_vel = cur_fdm_state->get_V_ground_speed()
// * SG_FEET_TO_METER * 60.0;
// double horiz_vel = airspeed_node->getFloatValue()
// * SG_FEET_TO_METER * 60.0;
gs_rate_of_climb_node
->setDoubleValue( -sin( des_angle * SGD_DEGREES_TO_RADIANS )
* horiz_vel * SG_METER_TO_FEET );
}
gs_rate_of_climb_node
->setDoubleValue( -sin( des_angle * SGD_DEGREES_TO_RADIANS )
* horiz_vel * SG_METER_TO_FEET );
void FGNavRadio::updateGPSSlaved()
{
has_gs_node->setBoolValue(gps_has_gs_node->getBoolValue());
_toFlag = gps_to_flag_node->getBoolValue();
_fromFlag = gps_from_flag_node->getBoolValue();
inrange_node->setBoolValue(_toFlag | _fromFlag);
_cdiDeflection = gps_cdi_deflection_node->getDoubleValue();
// clmap to some range (+/- 10 degrees) as the regular deflection
SG_CLAMP_RANGE(_cdiDeflection, -10.0, 10.0 );
_cdiCrossTrackErrorM = 0.0; // FIXME, supply this
_gsNeedleDeflection = 0.0; // FIXME, supply this
}
void FGNavRadio::updateCDI(double dt)
{
bool cdi_serviceable = cdi_serviceable_node->getBoolValue();
bool inrange = inrange_node->getBoolValue();
if (tofrom_serviceable_node->getBoolValue()) {
to_flag_node->setBoolValue(_toFlag);
from_flag_node->setBoolValue(_fromFlag);
} else {
to_flag_node->setBoolValue(false);
from_flag_node->setBoolValue(false);
}
if (!cdi_serviceable) {
_cdiDeflection = 0.0;
_cdiCrossTrackErrorM = 0.0;
}
cdi_deflection_node->setDoubleValue(_cdiDeflection);
cdi_xtrack_error_node->setDoubleValue(_cdiCrossTrackErrorM);
//////////////////////////////////////////////////////////
// compute an approximate ground track heading error
//////////////////////////////////////////////////////////
double hdg_error = 0.0;
if ( inrange && cdi_serviceable ) {
double vn = fgGetDouble( "/velocities/speed-north-fps" );
double ve = fgGetDouble( "/velocities/speed-east-fps" );
double gnd_trk_true = atan2( ve, vn ) * SGD_RADIANS_TO_DEGREES;
if ( gnd_trk_true < 0.0 ) { gnd_trk_true += 360.0; }
SGPropertyNode *true_hdg
= fgGetNode("/orientation/heading-deg", true);
hdg_error = gnd_trk_true - true_hdg->getDoubleValue();
// cout << "ground track = " << gnd_trk_true
// << " orientation = " << true_hdg->getDoubleValue() << endl;
}
cdi_xtrack_hdg_err_node->setDoubleValue( hdg_error );
//////////////////////////////////////////////////////////
// Calculate a suggested target heading to smoothly intercept
@ -644,34 +597,52 @@ bool FGNavRadio::updateWithPower(double dt)
// The cdi deflection should be +/-10 for a full range of deflection
// so multiplying this by 3 gives us +/- 30 degrees heading
// compensation.
double adjustment = cdi_deflection_node->getDoubleValue() * 3.0;
double adjustment = _cdiDeflection * 3.0;
SG_CLAMP_RANGE( adjustment, -30.0, 30.0 );
// determine the target heading to fly to intercept the
// tgt_radial = target radial (true) + cdi offset adjustmest -
// xtrack heading error adjustment
double nta_hdg;
if ( is_loc && backcourse_node->getBoolValue() ) {
double trtrue = target_radial_true_node->getDoubleValue();
if ( loc_node->getBoolValue() && backcourse_node->getBoolValue() ) {
// tuned to a localizer and backcourse mode activated
trtrue += 180.0; // reverse the target localizer heading
while ( trtrue > 360.0 ) { trtrue -= 360.0; }
SG_NORMALIZE_RANGE(trtrue, 0.0, 360.0);
nta_hdg = trtrue - adjustment - hdg_error;
} else {
nta_hdg = trtrue + adjustment - hdg_error;
}
while ( nta_hdg < 0.0 ) { nta_hdg += 360.0; }
while ( nta_hdg >= 360.0 ) { nta_hdg -= 360.0; }
SG_NORMALIZE_RANGE(nta_hdg, 0.0, 360.0);
target_auto_hdg_node->setDoubleValue( nta_hdg );
last_xtrack_error = xtrack_error;
last_loc_dist = loc_dist;
return inrange;
//////////////////////////////////////////////////////////
// compute the time to intercept selected radial (based on
// current and last cross track errors and dt
//////////////////////////////////////////////////////////
double t = 0.0;
if ( inrange && cdi_serviceable ) {
double xrate_ms = (last_xtrack_error - _cdiCrossTrackErrorM) / dt;
if ( fabs(xrate_ms) > 0.00001 ) {
t = _cdiCrossTrackErrorM / xrate_ms;
} else {
t = 9999.9;
}
}
time_to_intercept->setDoubleValue( t );
if (!gs_serviceable_node->getBoolValue() ) {
_gsNeedleDeflection = 0.0;
}
gs_deflection_node->setDoubleValue(_gsNeedleDeflection);
last_xtrack_error = _cdiCrossTrackErrorM;
}
void FGNavRadio::updateAudio(bool aInRange)
void FGNavRadio::updateAudio()
{
if (!_navaid || !aInRange || !nav_serviceable_node->getBoolValue()) {
if (!_navaid || !inrange_node->getBoolValue() || !nav_serviceable_node->getBoolValue()) {
return;
}

16
src/Instrumentation/navradio.hxx
View file

@ -124,7 +124,6 @@ class FGNavRadio : public SGSubsystem
bool has_dme;
double target_radial;
SGVec3d gs_base_vec;
double gs_dist_signed;
SGTimeStamp prev_time;
SGTimeStamp curr_time;
double effective_range;
@ -141,6 +140,12 @@ class FGNavRadio : public SGSubsystem
// internal periodic station search timer
double _time_before_search_sec;
// CDI properties
bool _toFlag, _fromFlag;
double _cdiDeflection;
double _cdiCrossTrackErrorM;
double _gsNeedleDeflection;
bool updateWithPower(double aDt);
// model standard VOR/DME/TACAN service volumes as per AIM 1-1-8
@ -151,9 +156,16 @@ class FGNavRadio : public SGSubsystem
double adjustILSRange( double stationElev, double aircraftElev,
double offsetDegrees, double distance );
void updateAudio(bool aInRange);
void updateAudio();
void audioNavidChanged();
void updateReceiver(double dt);
void updateGlideSlope(double dt, const SGVec3d& aircraft, double signal_quality_norm);
void updateGPSSlaved();
void updateCDI(double dt);
void clearOutputs();
FGNavRecord* findPrimaryNavaid(const SGGeod& aPos, double aFreqMHz);
public: